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GENERA   OF   SEALS                              453

the shoulders and extends to the thighs* like the other Seals
mentioned, the young are white "when first born. As may be
inferred from its scientific name this species is also Arctic in
range. It is also a rare visitor to these shores.
The genus Cystophora, is the only other genus of which there
is a [British representative. It is called the Hooded Seal on
account of an inflatable sac upon the face, with which it is said
to attempt to terrify its enemies. The genus has an incisor less
in each half of each jaw than fhoca, and Jfalichoerus. Its
formula is I -J while these genera are both -. O. cristatct, is a
large species reaching a length of 10 feet. The colour of the
back is dark grey with deeper coloured spots* A few individuals
only have been recorded from our coasts.
8tenor7iync7ius (  QgrnorJiinus) is an Antarctic genus. The
hind-feet are clawlesa The incisors are -|-. The molars have
an additional cusp, i.e. three in alL
The genus Leptomyzc with but one species, L. weddelli, is purely
Antarctic in range. Like the last genus it has two incisors, and
has but rudimentary claws upon the hind-feet; the first and fifth
toes moreover are the longest. The genus chiefly differs from
the last in the simple conical crowns of the molars, which have
not the additional cusps of Stenorhyneh'iLS.
Omma^opJiocct is another Antarctic genus with but a single
species, O, rossi. In this genus the hind-feet have no claws, and
the first and fifth toes are longer than the others. The claws of
the fore-feet are rudimentary. The immense size of the orbits
gives the name to the genus. There are two incisors, and the
molars are all very smalL
Mbnachits is a northern genus inhabiting the Mediterranean
and the Atlantic in the vicinity of Madeira and the Canary
Islands. Ifc has rudimentary nails upon both pail's of feet.
The first and fifth toe of the Mild-feet are longer than the
others. As with the preceding genera, the incisors are two in
each jaw. The species are Jf. albi'venter, the Monk-Seal, and
Jfl tropicalis, the Jamaica Seal.
Allied to Cystophora, is the genus Macrwrhivius, with (possibly)
two species, of which one is Antarctic, the other frecjuents or
frequented the coast of California. The incisors are two in.
the tipper jaw, and but one in the lower. The premolars are
four and the molar one; all the teeth, are small and simple, but